Pulse oximetry is a widely accepted noninvasive procedure for measuring the oxygen saturation level of arterial blood, an indicator of a person's oxygen supply. A typical pulse oximetry system has a sensor, a monitor and a patient cable providing a communication path between the sensor and monitor. The sensor is adapted to attach to a tissue site, such as a patient's finger, and respond to hemaglobin constituents of pulsatile blood. The monitor is adapted to receive a physiological signal from the sensor and provide a numeric readout of the patient's oxygen saturation and pulse rate.